Weigh-watchers everywhere, until now, could depend on one thing: No matter how much or how often they cheated on a diet, the refrigerator would never spill the beans.

But the days of silent nibbling may be over with the arrival of the latest weapon in the battle of the bulge - the talking refrigerator. Known as "The Diet Conscience." the device (which holds a tiny tape recorder) fits onto the inside of the refrigerator door and triggers one of four prerecouded messages every time the door is opened.

EATING AGAIN, NO WONDER YOU-RE GETTING SO FAT!" booms a man's voice. You also get "CALORIES, CALORIES, CALORIES" and a more subtle, "WHAT SUZE DID YOU SAY YOU WERE?"

Calorie-counters may find this latest assault on their willpower hard to stomach, but Caro Kielbala, a 36-year-old Palatine, III., housewife and inventor of "The Diet Conscience." says it works.

"I'm afraid to open the door," says the inventor, whose refrigerator and cupboard are both fitted with the device Kiebala, who at 5-feet-5 inches, an 140 pounds refers to herself as "(v. ORD ILLEGIBLE took her invention to New York's Lawrence Peska Associates. Inc. (the folks who brought us seat belts for dogs) who are curently manufacturing "The Diet COnscience." It will be available for $6.95 within the next two months, the company says.

"I always knew there was somebody in my refrigerator talking back to me." Kielbala says.

And now itwon't shut up.